Question: When was John D Rockefeller Jr. the spouse of Martha Baird?
Paraphrase: When was Martha Baird and John D Rockefeller Jr married?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q363984 p:P26 ?s . ?s ps:P26 wd:Q15730684 . ?s pq:P580 ?value}